Perennial Cover Crop Research

With the higher price of corn and soybeans earned by farmers the last three years and projected for the future, it appears that Midwest farmers are not going to be rotating to less profitable crops just for soil quality and environmental concerns.

That is why there is a need to come up with corn and soybean cropping systems that don’t cost farmers more than their current system, improves crop production performance and doesn’t appear to be hurting farmers’ fields, but actually improving them.

“Our role is to try crazy ideas and see if they work. It is up to industry to make them work in the real world,” said Ken Moore, Iowa State University, a teacher and researcher agronomy professor. Moore has overseen five years of continuous corn with a perennial cover crop research project.

Moore’s preferred perennial cover crop in the ISU trial has been Kentucky bluegrass. The grass is not killed from year to year. “You treat it like a weed in the spring, and you treat it in the summer like a mulch, and you treat it in the fall like a cover crop,” Moore said. “We don’t kill it in the spring; we just set it back by burning it off with a product like Paraquat. It is not really competing with the corn plant directly for nutrients all that seriously.”

The above ground foliage is killed, but the roots are alive, and it comes back if there is water during the growing season. Putting the grass into something like a hibernation state during the early spring is necessary. It is important to control the potentially competitive grass so “that corn can achieve its maximum yield potential.”

In the five years of plot trials, the planting strips and the grass between rows have been kept constant. “It might make sense at some point to reseed and re-establish the strips different than where the rows have been,” Moore said.

2012 DROUGHT CAUSED FAILURE

“This is the first year of the five that the system didn’t really perform well,” Moore explained. “I can tell you it doesn’t work in a drought, at least not a drought to the extent that we had this year.”

“I’ve talked to people who laugh us off until I tell them we harvested 240 bushels of corn per acre in perennial cover crop plots, actually multiple plots in 2011.”

He said, “We have been trying to tell producers in particular that this is a pretty brittle system and not something you should try. It is more likely to fail than work at this point, although we do believe it can work, and we have been able to demonstrate that four out of five years.”

Industry needs to step up to help farmers to meet the environmental issues that are going to become more of a concern instead of going away. Regulatory oversight appears to be increasing, and the general public is blaming farmers for polluting the environment—soil erosion, nitrate water pollution and more.

One of the ideas of using a perennial cover crop has to do with the potential for allowing a high level of corn stover to be harvested for cellulosic ethanol while helping soil quality and still limiting soil erosion.

Moore suggests that seed companies need to invest in developing hybrids, other crop varieties and cover crops specifically for perennial cover crop systems. “I think the onus is on the industry, the seed industry in particular to make this system practical. It answers a lot of problems. The environmental issues keep coming up and up; they are real problems for the industry that need to be addressed in some way, and this is one way. It might not be the only or best way, but it is a way they should take a look at.”